The present invention relates to a valve device, in particular a valve device for controlling access to a container with an inclined wall.
In the production of pharmaceutical tablets, for example, it is necessary to periodically introduce the component materials into a mixer granulator. Typically, the mixer granulator comprises a generally cylindrical bowl with a lid which has the same diameter as the bowl and is fitted with air filters.
Conventionally, it has been necessary to manually open and shut the lid of the bowl when fresh material needs to be fed to the mixer granulator. This makes continuous feeding difficult and allows the material to come into contact with the ambient atmosphere. A known mixing or granulating apparatus having a disc valve is disclosed in GB-A-2091625. Also, GB-A-2100610 shows a known mixer-granulator drier having a slide valve.